Cognitive testing is limited in its ability to differentiate between adults with bipolar disorder (BD) who had childhood attention-deficit/hyperactivity disorder (ADHD) and those who did not, according to a study published in the International Journal of Bipolar Disorders.
The study included adult patients with BD either with (n=32) or without (n=66) childhood ADHD and healthy control individuals (n=112) recruited from a bipolar outpatient clinic at the Northern Stockholm psychiatric clinic in Sweden between October 2005 and April 2008. Investigators conducted diagnostic assessments and parent or next-of-kin interviews to establish childhood ADHD as well as extensive neuropsychological assessments, including cognitive tests for verbal memory, attention, executive function, and working memory.
Overall, patients with BD in the groups with and without childhood ADHD had similar neuropsychological profiles. However, the group with childhood ADHD performed significantly worse on working memory than the group without childhood ADHD. There were no differences in working memory between patients with childhood ADHD and those who continued to meet criteria for ADHD in adulthood. When the healthy control group was added to the comparisons, working memory was no longer statistically significant between the groups with BD.
Results were not corrected for multiple comparisons. In addition, the limited number of study subjects might have affected the possibility to detect group differences, and patients’ use of mood stabilizer medications may have affected cognitive performance.
“[F]uture research could investigate in more detail if cognitive testing focusing on working memory together with a thorough assessment of childhood symptoms of ADHD might be of value in identifying a group of BD patients at risk for poor outcomes,” concluded the investigators.
Salarvan S, Sparding T, Clements C, Rydén E, Landén M. Neuropsychological profiles of adult bipolar disorder patients with and without comorbid attention-deficit hyperactivity disorder. Int J Bipolar Disord. 2019;7(1):14.